Improvement in raising sunken vessels



R. W. HALLETT.

y Raising Snken Vessels.

NO SMSBQ 4 l PatentedMa1|chl8,1873.

s WWNESSES. l

INVENTOR.

UNITED STATES PATENT OEEIoE.

RICHARD w. EALLETT, or BROOKLYN, E. D., NEW Yoan.

IMPROVEMENT IN RAISING suNKEN vEssELs.

Specification forming part of Letters Patent No. 136,832, dated MarchL8, 1873.

'Nature and Object.

This invention consists in the combination of regulating-lioats with thebuoys orlightering-tanks, whose displacement liftsthe vessel in such amanner that said iioats shall determine the depth to which the buoys ortanks may be sunk, so that anyrequired depth may be given to the tanksprevious to their connec- `tion with the vessel, and at the same time beprevented from sinking to the bottoni.v

Drawing.

The letter A in the drawing, represents a cross-section of a vessel,upon the sides ot which are lashed the tanks or` buoys B B by chains ora chain, as at'C,-attached to each of the tanks and passing aroundunderneath the bottom and the .keel of the ship, and by the displacementof said tanks the vessel is lifted or lightered77 to such a degree astobe carried over said bars or other obstructions. But in order toobtain the full lifting capacity of the tanks it is necessary that theyshall be sunk to the full extent of their displacement, and to maintainthey mustalso besunk to as great or greater depthpbe'lofw the surface asthe vessel is to be lifted, otherwise, when they begin to rise above thesurface they begin to lose their lifting power. It is also necessary,for the saving of time, that said tanks should not be permitted to sinkto the bottom, but be maintained at about the proper depth for thechains C to swing easily under the vessel, due allowance being made forher breadth of beam, so that the tanks may be towed along on each sidein about the position to begin the operation of lightering as soon asthe vessel approaches the bar or obstruction. To secure these advantageseach tank is provided with sufficient sustainingcapacity to sustain thevweight of the tanks B Bwhen illed with water, and maintain them' at anydesired depth. To these oats the tanks are connected by chains or otherregulating attachment, as at E E', by which the depth of the tank may begraduated before any connection is made with the vessel-the simplestmanner being by slipping a toggle or pin through the links, asrepresented in the drawing.

It is preferable to make said floats with a cross-section of triangularform, as shown at D D', as thereby the upper side can always be keptuppermost, and the chains that connect them with the tanks may passthrough tubes extending vertically through them.

Similar tubes may also extend through the tanks, but in the direction ofthe force to be exerted. The tanks may also be provided withcompartments into which the water cannot enter; said compartments havingsufficient displacement to equalize the weight of the tank itself', andthereby dispense with thewusem less charging and discharging of so muchwater.

Valves as at F, where one of the tanks is shown in section, may be usedto let the water into it; but a tube as at Gr, for the outlet of thewater or air, as desired, may be extended up above the surface, and befurnished with a stop-cock, so that ahole may be left in the bottom forthe free passage of the water.

' These devices, however, as also the construction of the tanks, are allwell known and do not form a part ot' this invention; but

I do claim- In an apparatus forlightering ships and other similarvessels over bars and other obstructions, the combination of theregulating'- ioats with the lightering-tanks, substantially as describedand for the purposes set forth. RICHARD W. HALLETT.

Witnesses:

E. N. ELIOT, A. MOORE.

